Search Publications
The Herschel/HIFI spectral survey of OMC-2 FIR 4 (CHESS). An overview of the 480 to 1902 GHz range
Ceccarelli, C.; Dominik, C.; Caux, E. +6 more
Context. Broadband spectral surveys of protostars offer a rich view of the physical, chemical and dynamical structure and evolution of star-forming regions. The Herschel Space Observatory opened up the terahertz regime to such surveys, giving access to the fundamental transitions of many hydrides and to the high-energy transitions of many other sp…
Age dating stellar populations in the near infrared: an absolute age indicator from the presence/absence of red supergiants.
Bastian, N.; Adamo, A.; Urbaneja, M. A. +4 more
The determination of age is a critical component in the study of a population of stellar clusters. In this Letter, we present a new absolute age indicator for young massive star clusters based on J-H colour. This novel method identifies clusters as older or younger than 5.7 ± 0.8 Myr based on the appearance of the first population of red supergian…
Ripping apart at the seams: the network of stripped gas surrounding M86
Finoguenov, A.; Simionescu, A.; Allen, S. W. +4 more
We present a new study of the Virgo Cluster galaxies M86, M84, NGC 4338 and NGC 4438 using a mosaic of five separate pointings with XMM-Newton. Our observations allow for robust measurements of the temperature and metallicity structure of each galaxy along with the entire ∼1° region between these galaxies. When combined with multiwavelength observ…
3D morphometry of valley networks on Mars from HRSC/MEX DEMs: Implications for climatic evolution through time
Mangold, N.; Ansan, V.
valley networks have been identified mainly in the Noachian heavily cratered uplands. Eight dense branching valley networks were studied in Noachian terrains of Huygens, Newcomb and Kepler craters, south Tyrrhena Terra, and Thaumasia, in Hesperian terrains of Echus Plateau and west Eberswalde craters, and in Amazonian terrains of Alba Patera, usin…
Comparing the White Dwarf Cooling Sequences in 47 Tuc and NGC 6397
Dotter, Aaron; Rich, R. Michael; Richer, Harvey B. +7 more
Using deep Hubble Space Telescope imaging, color-magnitude diagrams are constructed for the globular clusters 47 Tuc and NGC 6397. As expected, because of its lower metal abundance, the main sequence of NGC 6397 lies well to the blue of that of 47 Tuc. A comparison of the white dwarf cooling sequences of the two clusters, however, demonstrates tha…
Orbital and evolutionary constraints on the planet hosting binary GJ 86 from the Hubble Space Telescope
Bond, Howard E.; Barstow, M. A.; Holberg, J. B. +5 more
This paper presents new observations of the planet-hosting, visual binary GJ 86 (HR 637) using the Hubble Space Telescope. Ultraviolet and optical imaging with WFC3 confirms the stellar companion is a degenerate star and indicates the binary semimajor axis is larger than previous estimates, with a ≳ 28 au. Optical STIS spectroscopy of the secondar…
Hot flow anomaly formation and evolution: Cluster observations
Zong, Qiugang; Zhang, Hui; Wang, Shan
In this study, we have examined the formation and evolution of 513 hot flow anomalies (HFAs) from 2003 to 2009 observed by the Cluster spacecraft. Our results show that an original upstream discontinuity in the vicinity of an HFAs and/or at least one side of the HFA with the convective electric field pointing toward the discontinuity may help an H…
Near-infrared optical constants of naturally occurring olivine and synthetic pyroxene as a function of mineral composition
Trang, David; Gillis-Davis, Jeffrey J.; Klima, Rachel L. +3 more
Radiative transfer theory will assist in determining olivine and pyroxene proportions and compositions from the surface of a planetary body composed of intimately mixed minerals. In order to use radiative transfer techniques, the model requires the optical constants of olivine and pyroxene. Optical constants are parameters that describe the degree…
Spectroscopic classification of icy satellites of Saturn I: Identification of terrain units on Dione
Stephan, K.; Capaccioni, F.; Cerroni, P. +4 more
Dione is one of the largest and densest icy satellites of Saturn. Its surface shows a marked asymmetry between its leading and trailing hemispheres, the leading side being brighter than the trailing side, which shows regions mantled by a dark veneer whose origin is likely exogenic. In order to identify different terrain units we applied the Spectr…
An MHD simulation model of time-dependent global solar corona with temporally varying solar-surface magnetic field maps
Hayashi, K.
We present a model of a time-dependent three-dimensional magnetohydrodynamics simulation of the sub-Alfvenic solar corona and super-Alfvenic solar wind with temporally varying solar-surface boundary magnetic field data. To (i) accommodate observational data with a somewhat arbitrarily evolving solar photospheric magnetic field as the boundary valu…